System and method for preventing display bowing

ABSTRACT

An apparatus for preventing bowing of an electronic display includes a housing and a cover panel. The electronic display is located behind said cover panel, and a backlight is located behind said electronic display. A closed loop pathway for circulating gas includes a first gas pathway located between said cover panel and the electronic display, a backlight cavity located between the electronic display and the backlight, and a second gas pathway located behind the backlight.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional patentapplication Ser. No. 62/491,123 filed Apr. 27, 2017, which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention relate generally toassemblies for electronic displays.

BACKGROUND AND SUMMARY OF THE INVENTION

Electronic displays have grown in popularity not only for indoor use,but also for outdoor use. One exemplary application, without limitation,is the digital out of home market where the electronic displays areincreasingly replacing the use of static posters. The use of electronicdisplays is advantageous because they allow images to be changed quicklyas well as permit the use videos and interactive displays, among otherbenefits. Such displays may be used for advertisements, publicannouncements, information, wayfinding, and the like.

Such outdoor, and some indoor, displays are sometimes encased in ahousing to protect them from environmental conditions. The housing maybe designed to resist, mitigate, manage, control, or prevent water,precipitation, dust, and air contaminant intrusion, vandalism,tampering, wind, temperature changes, solar loading, extremetemperatures, and the like. Oftentimes, these displays are placedoutdoors where they are subject to extreme temperatures, drastictemperature changes, and significant solar loading. If the temperatureinside the housing gets too high or too low the electronic displays andrelated components may be damaged. As such, the temperature inside thehousing must be maintained at acceptable levels. In order to maintainthe temperature inside the housings at acceptable levels, a number ofgas pathways are generally placed through the housing. Sometimes, acombination of open loops carrying ambient air and closed loops carryingcirculating gas are used.

Over time, the market has demanded increasingly larger displays. Theselarger displays have correspondingly larger surface areas and oftenrequire correspondingly larger, in size or number, gas pathways tomaintain the temperature in the housing. As the dimensions of thesedisplays and corresponding gas pathways have increased, the potentialfor the displays to bow outwardly has increased. This is because,typically, the displays are mostly unsupported. The displays aregenerally mounted along their perimeter so illumination from thebacklight is permitted to reach the entirety of the display, among otherconsiderations. Thus, a large section of the display is not directlymounted to a housing or other stabilizing or supporting structure, whichmay allow bowing of the display. Additionally, the asymmetricaltemperature loading of various layers and components of the display maycontribute to such display bowing. Further still, some displays have agap between the electronic display itself and a cover panel located infront of the electronic display. As the electronic display bows towardsthe cover panel, the gap between the cover panel and the display may benarrowed and a resulting venturi effect may be created. The venturieffect may increase the bowing forces.

Such bowing can cause damage to the display, distortion of the displayedimage, and may disrupt airflow through the open and closed loops. Insome cases, the electronic display may bow outwardly enough that itcontacts the cover panel. This may not only interrupt normal thermalmanagement but may also result in significant heat transfer from thesolar loaded cover panel to the electronic display. This may rapidlycause permanent damage to the display. Therefore, what is needed is asystem and method for preventing an electronic display from bowing.

Additionally, display assemblies comprising a backlight sometimes have asealed cavity for the backlight. As the illumination devices and othercomponents of the backlight generate heat, heat can become trapped inthis cavity. Because the cavity may be completely or partially sealed,the heat may build up and cause damage to components of the assembly.Therefore, what is needed is a system and method for removing heat fromthe backlight cavity.

The present invention is a system and method for preventing anelectronic display from bowing. The present invention is also a systemand method for removing heat from the backlight cavity. The presentinvention provides a first gas pathway through first gas pathwaysbetween a cover panel and an electronic display and an additional flowpath through a backlight cavity located in the space between theelectronic display and a backlight. The flow of air through thebacklight cavity removes heat from the backlight cavity generated by theillumination devices or other components.

The amount or speed of airflow through the first gas pathway and thebacklight cavity may be controlled so as to create a pressure drop inthe backlight cavity as compared to the first gas pathway. This pressuredrop may result in forces which tend to pull the electronic display awayfrom the cover panel, thereby reducing or eliminating the bowing. Inparticular, a support or a bracket may be used to create an entrance gapand exit gap into and out of the backlight cavity. In this way theamount or speed of airflow through the backlight cavity may becontrolled. The entrance gap may be smaller than the exit gap. Inexemplary embodiments, an angled section may extend from the distal endof the bracket located near the exit gap. The angled section may extendtowards the side of the housing to restrict the flow of air from thefirst gas pathway into a second gas pathway located behind thebacklight. The constriction of this air may create a venturi effect,creating a low-pressure zone near the angled section to pull circulatinggas through the backlight cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

In addition to the features mentioned above, other aspects of thepresent invention will be readily apparent from the followingdescriptions of the drawings and exemplary embodiments, wherein likereference numerals across the several views refer to identical orequivalent features, and wherein:

FIG. 1 is a perspective view of an exemplary display assembly inaccordance with the present invention also indicating section lines A-A;

FIG. 2 is a top sectional view of an exemplary display assemblyembodiment taken along section line A-A of FIG. 1;

FIG. 3 is a top sectional view of another exemplary display assemblyembodiment taken along section line A-A of FIG. 1;

FIG. 4 is a top section view similar to FIG. 2 illustrating an exemplarypressure analysis where the display bowing is reduced or eliminated;

FIG. 5 is a top section view similar to FIG. 3 illustrating anotherexemplary pressure analysis where the display bowing is reduced oreliminated;

FIG. 6 is an exemplary graphical representation of another exemplarypressure analysis;

FIG. 7A is a side view of another exemplary display assembly inaccordance with the present invention;

FIG. 7B is a front view of the display assembly of FIG. 7A alsoindicating section line B-B;

FIG. 8 is a top sectional view taken along section line B-B of FIG. 7Balso indicating detail A;

FIG. 9 is a detailed top sectional view of Detail A of FIG. 8;

FIG. 10 is a front perspective view of another exemplary displayassembly in accordance with the present invention also indicatingsection line C-C;

FIG. 11 is a top perspective sectional view taken along section line C-Cof FIG. 10 also indicating Detail B and Detail C;

FIG. 12 is a detailed top sectional perspective view of Detail B of FIG.11;

FIG. 13 provides another angle of Detail B of FIGS. 11-12;

FIG. 14 is a detailed top perspective sectional view of Detail C of FIG.11;

FIG. 15 is a detailed top perspective sectional view similar to FIG. 14illustrated in greater detail and from a different angle;

FIG. 16 is another exemplary pressure analysis similar to FIG. 6;

FIG. 17 is a top sectional view similar to FIG. 11 showing an exemplaryair flow velocity analysis also indicating Detail D and Detail E;

FIG. 18 is a detailed top sectional view of Detail D of FIG. 17; and

FIG. 19 is a detailed top sectional view of Detail E of FIG. 17.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

Various embodiments of the present invention will now be described indetail with reference to the accompanying drawings. In the followingdescription, specific details such as detailed configuration andcomponents are merely provided to assist the overall understanding ofthese embodiments of the present invention. Therefore, it should beapparent to those skilled in the art that various changes andmodifications of the embodiments described herein can be made withoutdeparting from the scope and spirit of the present invention. Inaddition, descriptions of well-known functions and constructions areomitted for clarity and conciseness.

FIG. 1 is a perspective view of an exemplary display assembly 10 inaccordance with the present invention also indicating section line A-A.The display assembly 10 may comprise an electronic display 14 located ina housing 16. In exemplary embodiments, the electronic display 14 is aliquid crystal display (LCD). However, any type of electronic display 14may be used, such as but not limited to, a LCD, light emitting diode(LED) display, organic LED display, plasma display, or the like. Theelectronic display 14 may optionally comprise one or more diffusersheets or optical films. A cover panel 12 may be located in front of theelectronic display 14. The cover panel 12 may be located substantiallyparallel to, spaced apart from, and in front of the electronic display14. The cover panel 12 may form the front surface of the housing 16. Thecover panel 12 may be comprised or a transparent or translucent materialsuch as, but not limited to, a glass or acrylic. The cover panel 12 maybe comprised or multiple layers. As will be shown and described ingreater detail herein, one or more electronic displays 14 andcorresponding components may be used, including but not limited to, apair of electronic displays 14 placed back to back within the housing16. Regardless, an intake 18 may extend along either side or the upperportion of the housing 16, though any location is contemplated. As willbe shown and described in greater detail herein, an exhaust 20 may belocated along the lower edge of the display assembly 10, though anylocation is contemplated.

FIG. 2 is a top section view taken along section line A-A of FIG. 1illustrating an exemplary display assembly 10 using a single electronicdisplay 14. A backlight 30 may be located behind the electronic display.The backlight 30 may be located behind, substantially parallel to, andspaced apart from, the electronic display 14. The backlight 30 maycomprise a number of illumination devices, such as but not limited tolight emitting diodes (LEDs), located on a pan. In exemplaryembodiments, the backlight 30 may comprise a number of illuminationdevices arranged in a spaced pattern to provide a directly backlitarrangement. In other exemplary embodiments, the backlight 30 maycomprise a number of illumination devices arranged in a line along oneor more sides of the electronic display 14 in an edge lit arrangements.In still other exemplary embodiments, the backlight 30 may form a partof the electronic display 14, such as without limitation with an organicLED display. In such embodiments, a backlight pan may be located behindthe electronic display 14. The backlight pan may be a metal sheet or thelike.

Regardless, a rear plate 32 may be located behind the backlight 30. Therear plate 32 may be located behind, spaced apart from, andsubstantially parallel to the backlight 30. A first gas pathway 22 maybe located in the space between the rear surface of the cover panel 12and the front surface of the electronic display 14. This space may alsobe referred to as the LCD cavity herein. The first gas pathway 22 may beconfigured to receive circulating gas 24. The circulating gas 24 maytravel through the first gas pathway 22 and into a second gas pathway 26located behind the backlight 30.

The second gas pathway 26 may be located in the space between the rearplate 32 and the rear of the housing 16. The second gas pathway 26 maycomprise a heat exchanger 28 and an electronics cavity 30, though suchis not required. The heat exchanger 28 may be any type of heat exchanger28. The heat exchanger 28 may be mounted to the rear plate 32, thoughany location is contemplated. In exemplary embodiments, the heatexchanger 28 occupies a first portion of the second gas pathway 26 andthe electronics cavity 34 occupies a second portion where variouselectronic components may be located. The heat exchanger 28 may also bepart of a second open loop pathway. These various electronic componentsmay be used to operate the display assembly 10. After traveling throughthe second gas pathway 26, the circulating gas 24 may return to thefirst gas pathway 22, thus creating a closed loop. Stated another way,the closed loop may encircle the electronic display 14. One or moreclosed loop fans 35 may be placed along the closed loop so as to controlthe speed and amount of circulating gas 24 pass through the closed loop,or through the first gas pathway 22 or the second gas pathway 26. Inexemplary embodiments, the closed loop fan 35 may be located between theheat exchanger 28 and the electronics cavity 34, though any location iscontemplated.

In exemplary embodiments, a corrugation layer 38 may be located betweenthe rear surface of the backlight 30 and the front surface of the rearplate 32. The corrugation layer 38 may be configured to receive ambientair 44. The space between the rear plate 32 and the backlight 30 maydefine a first open loop channel 37. The ambient air 44 may also flowthrough the heat exchanger 28 (the second open loop pathway). Ambientair 44 may enter the assembly 10, pass through the first or second openloop pathways and then exit the assembly 10, thus creating an open loop.One or more open loop fans 33 may be placed along the open loop tocontrol the amount or speed of ambient air 44 flowing through the openloop, or through the corrugation layer 38 or the heat exchanger 28.

A backlight cavity 36 may be located in the space between the rearsurface of the electronic display 14 and the front surface of thebacklight 30. A portion of the circulating gas 24 may be separated fromthe remainder of the circulating gas 24 and travel into or through thebacklight cavity 36. This portion of the circulating gas 24 may also bereferred to herein as the backlight cavity gas 25. The backlight cavitygas 25 that exits the backlight cavity 36 may be rejoined with thecirculating gas 24. The backlight cavity 36 may be framed on the sides,at least in part, by supports 47. In exemplary embodiments, a firstsupports 47 is located on the side of the backlight cavity 36 whichreceives the backlight cavity gas 25 and a second support 47 is locatedon the side of the backlight cavity 36 where the backlight cavity gas 25exits the backlight cavity 36.

The supports 47 may extend from the rear surface of the electronicdisplay 14 to support various components, such as but not limited to, adiffuser, optical films, a transparent sheet, or the like, locatedbetween the electronic display 14 and the backlight 30. The supports 47may be spaced apart from the backlight 30 or the electronic display 14at one or more locations to define an entrance gap and an exit gap forthe backlight cavity gas 25 to enter or exit the backlight cavity 36,respectively. In other exemplary embodiments, the supports 47 maycomprise a number of aperture which define the entrance gap and the exitgap. As will be explained in greater detail herein, the backlight cavitygas 25 may be maintained at a lower pressure relative to the circulatinggas 24 traveling through the first gas pathway 22, though such is notrequired.

In exemplary embodiments, the pressure of the backlight cavity gas 25may be kept relatively low by controlling the amount or speed of thebacklight cavity gas 25 permitted to enter and exit the backlight cavity36. The amount or speed of the backlight cavity gas 25 may becontrolled, at least in part, by the dimensions and/or shape of thebacklight cavity 36. In exemplary embodiments, the gap between thesupports 47 and the front surface of the backlight 30 may be sized andconfigured to control the amount or speed of the backlight cavity gas 25allowed to enter and exit the backlight cavity 36. In exemplaryembodiments, the gap between the support 47 located at the entrance tothe backlight cavity 36 may be smaller than the gap between the support47 located at the exit of the backlight cavity 36 to reduce the pressureof the backlight cavity gas 25.

Alternatively, or in addition, the amount or speed of air permitted toenter and exit the backlight cavity 36 may be controlled by brackets 48.In exemplary embodiments, a first bracket 48 is located on the side ofthe backlight cavity 36 which receives the backlight cavity gas 25 and asecond bracket 48 is located on the side of the backlight cavity 36where the backlight cavity gas 25 exits the backlight cavity 36. Thebrackets 48 may be substantially shaped as an upside-down “L” and mayextend from either edge of the electronic display 14 so as to also framethe backlight cavity 36. The gap between the bracket 48 and thesurrounding structure, including but not limited to, the backlight 30and the corrugation layer 38, may be sized and configured to control theamount or speed of the backlight cavity gas 25 allowed to enter and exitthe backlight cavity 36. In exemplary embodiments, the gap between thebracket 48 located at the entrance to the backlight cavity 36 may besmaller than the gap between the bracket 48 located at the exit of thebacklight cavity 36 to reduce the pressure of the backlight cavity gas25.

In exemplary embodiments, some or all of the brackets 48 may comprise anangled section 49 extending from an end thereof. This angled section 49may be angled, oriented, sized, shaped, and otherwise configured tolikewise to control the amount or speed of the backlight cavity gas 25allowed to enter and exit the backlight cavity 36. In exemplaryembodiments, the angled section 49 may only be located on the exit ofthe backlight cavity 36 to assist in reducing the pressure of thebacklight cavity gas 25.

In exemplary embodiments, the angled section 49 may extend towards theside of the housing. The angled section 49 may extend into the flow ofcirculating gas 24 passing from the first gas pathway 22 into the secondgas pathway 26. The angled section 49 may disrupt a portion of such flowand instead permit said backlight cavity gas 25 to rejoin the remainderof the circulating gas 26. As the angled section 49 may restrict theflow of circulating gas 24 passing from the first gas pathway 22 intothe second gas pathway 26, the angled section 49 may create a venturieffect and result in a lower pressure area near the exit of thebacklight cavity 36. This lower pressure area may force or encourage thebacklight cavity gas 25 to enter, flow through, and exit the backlightcavity 36. This may affect the relatively pressure of the backlightcavity gas 25 and the resulting forces on the electronic display 14. Theangle of the angled section 49 may be engineered and adjusted to providea desirable flow through the backlight cavity 36 and resulting force onthe electronic display 14.

The amount or speed of the circulating gas 24 permitted to enter andexit the backlight cavity 38 (the backlight cavity gas 25) may bepredetermined to account for anticipated bowing of the electronicdisplay 14. Indeed, the amount or speed of the backlight cavity gas 25may determine the pressure of the backlight cavity gas 25, and thus theresulting force on the electronic display 14. For example, withoutlimitation, enough resulting force may be desirable to substantiallycancel out the bowing of the electronic display 14. However, too muchresulting force may compress the electronic display 14, resulting inimage distortion and/or damage to the electronic display 14. Inexemplary embodiments, a pressure difference between 0-0.5 psi betweenthe circulating gas 24 flowing through the first gas pathway 22 and thebacklight cavity gas 25 may be desirable, though any relative pressuresare contemplated. For example, without limitation, the supports 47, thebrackets 48, and the angled section 49 may be sized to create apredetermined relative pressure drop. Similarly, the angle of the angledsection 49 may be selected to create a predetermined relative pressuredrop. It is contemplated that other control devices may be used tocontrol the amount or speed of the backlight cavity gas 25 such as,without limitation, fans, structural obstructions, diffusers, filters,throttles, valves, flow splitters, or the like.

FIG. 3 is a top sectional view of another exemplary display assembly 10embodiment taken along section line A-A of FIG. 1. The display assembly10 illustrated and described with respect to FIG. 3 is similar to thedisplay assembly 10 illustrated with respect to FIG. 2 with the additionof a second electronic display 14 placed back to back with the firstelectronic display 14. Related components for the second electronicdisplay, such as but not limited to, a second cover panel 12, a secondbacklight cavity 36, may likewise be placed back to back with the firstelectronic display 14. In this embodiment, the circulating gas 24 mayseparate after traveling through the second gas pathway 26 such that aportion flows in front of each electronic display 14. Similarly, aportion of the circulating gas 24 may be separated and may flow asbacklight cavity gas 25 through each respective backlight cavity 36. Thecirculating gas 24 flowing in front of each of the respective electronicdisplay 14 may be rejoined at the other end of the first gas pathway 22and flow through the second gas pathway 26. In such embodiments, thesecond gas pathway 26 may share a common heat exchanger 28, electronics,electronics cavity 34, and other related components, though such is notrequired. It is contemplated that separate closed loop pathways mayinstead be utilized. It is further contemplated that additionalelectronic displays 14 in various locations are contemplated.

FIG. 4 is a top sectional view similar to FIG. 2 illustrating anexemplary pressure analysis for the display assembly 10. Similarly, FIG.5 is a top sectional view similar to FIG. 3 illustrating an exemplarypressure analysis for the display assembly 10. FIGS. 4 and 5 demonstratehow bowing of the electronic display 14 may be reduced or eliminated.These analyses are merely exemplary and are not intended to be limiting.Any dimensions, temperatures, pressures, and the like are contemplated.

As can be seen in both FIG. 4 and FIG. 5, the pressure of the backlightcavity gas 25 located in the backlight cavity 38 is relatively low ascompared to the pressure of the circulating gas 24 located in the firstgas pathway 22 along the entirety of the first gas pathway 22. Forexample, but not to serve as a limitation, the pressure of the backlightcavity gas 25 is illustrated as green, thereby indicating a lowerpressure, as compared to the pressure of the circulating gas 24 in thefirst gas pathway 22 which is illustrated yellow to indicate a higherpressure. The indicated pressure drop may create forces which counteractthe bowing of the electronic display 14 that may otherwise occur,leading to decreased or eliminated bowing of the electronic display 14as shown.

FIG. 6 is an exemplary graphical representation of another exemplarypressure analysis illustrating differential pressure between the firstgas pathway 22 (also referred to as the LCD cavity, the front glass airgap, or the LCD-front glass air gap herein) and the backlight cavity 36(also referred to as the LED cavity herein). This analysis and theresults are merely exemplary and are not intended to be limiting. Anydimensions, temperatures, pressures, and the like are contemplated. Thedetailed data used to produce the graphical representation shown in FIG.6 is as follows:

LCD-Front Glass Air Gap Data

TABLE 1 X Y Z Abs Pressure Temperature [in] [in] [in] [lbf/in{circumflexover ( )}2] (Fluid) [° C.] 28 −14 4.25 15.64857752 80.1480277 14 −144.25 15.64646607 79.09110465 0 −14 4.25 15.6454628 75.28046445 −14 −144.25 15.6448872 75.11193992 −28 −14 4.25 15.64592538 73.22106961 28 04.25 15.65053391 76.47154539 14 0 4.25 15.64905628 76.15458164 0 0 4.2515.64821219 72.39194399 −14 0 4.25 15.64801795 71.92009026 −28 0 4.2515.64829522 69.78575356 28 14 4.25 15.65330566 72.50363672 14 14 4.2515.65321209 71.96269658 0 14 4.25 15.65307815 67.82091386 −14 14 4.2515.65242712 67.46451856 −28 14 4.25 15.65168999 65.76823918

LED Cavity (ABS Pressure PSI) Data

TABLE 2 X Y Z Abs Pressure Temperature [in] [in] [in] [lbf/in{circumflexover ( )}2] (Fluid) [° C.] 28 −14 3.37 15.64622021 87.70353149 14 −143.37 15.64566772 87.96110944 0 −14 3.37 15.64512518 91.58209795 −14 −143.37 15.644584 79.94765992 −28 −14 3.37 15.64401504 79.7297815 28 0 3.3715.64615716 88.11894204 14 0 3.37 15.64556531 86.24853469 0 0 3.3715.64509058 77.61667113 −14 0 3.37 15.64448586 75.67236919 −28 0 3.3715.64400603 74.72774976 28 14 3.37 15.64606925 89.41494757 14 14 3.3715.64557001 82.3178322 0 14 3.37 15.6449758 83.04160394 −14 14 3.3715.64443134 76.65225751 −28 14 3.37 15.64397409 71.0659114

Differential Pressure (LCD-LED) (PSI)

TABLE 3 0.002357311 0.000798346 0.000337611 0.000303201 0.0019103360.004376755 0.003490969 0.003121612 0.003532089 0.004289189 0.0072364180.007642077 0.008102352 0.007995777 0.0077159

Chart Data

TABLE 4 −14 0 14 28 0.002357 0.004377 0.007236 14 0.000798 0.0034910.007642 0 0.000338 0.003122 0.008102 −14 0.000303 0.003532 0.007996 −280.00191 0.004289 0.007716

As can be seen, the pressure of the backlight cavity gas 25 located inthe backlight cavity 38 is relatively low as compared to the pressure ofthe circulating gas 24 located in the first gas pathway 22 along theentirety of the first gas pathway 22. The resulting pressure drop maycreate forces which counteract the bowing of the electronic display 14that may otherwise occur, leading to decreased or eliminated bowing asshown in this figure. It is notable that while the pressure differential(here, a relative pressure drop) between the data points in thebacklight cavity 36 and the corresponding data points in the first gaspathway 22 may be relatively small, when multiplied by the number ofsquare inches in the corresponding electronic display 14, the resultingforces can be significant.

FIG. 7A and FIG. 7B illustrate another exemplary display assembly 10 inaccordance with the present invention. Ambient air 44 may be ingestedinto the top of the display assembly 10 and exhausted from the bottom ofthe display assembly 10, thus creating an open loop.

FIG. 8 and FIG. 9 illustrate another exemplary embodiment of the displayassembly 10. As illustrated, circulating gas 24 may flow through theelectronics cavity 34. A first portion of the circulating gas 24 mayenter the first gas pathway 22, and a second portion of the circulatinggas 24 may enter the backlight cavity 36 (i.e., the backlight cavity gas25). The circulating gas 24 be rejoined when exiting the first gaspathway 22 and the backlight cavity 36 and returning to the electronicscavity 34, thus creating a closed loop. The electronics cavity 34 maycomprise one or more heat exchangers 28, though such is not required. Inexemplary embodiments, the heat exchanger 28 may comprise one or moreclosed loop channels 29 for the circulating gas 24. Ambient air 44 maytravel through one or more of the first open loop channels 37. Theambient air 44 may also travel through one or more open loop channels 27in the heat exchanger 28.

FIG. 10 through FIG. 15 illustrate another exemplary embodiment of thedisplay assembly 10. This embodiment may likewise comprise supports 47,brackets 48, and an angled section 49 similar to those described herein.Multiple angled sections 49 may extend from the brackets 48.

A first exit gap 45 may be located between the support 47 and the rearplate 32. In exemplary embodiments, the second exit gap 43 may belocated between a distal end of the support 47 and the front surface ofthe rear plate 32. A second exit gap 43 may be located between thebracket 48 and the housing 16. Alternatively, or in addition the secondexit gap 43 may be located between the angled section 49 and the housing16. In exemplary embodiments the portion of the housing 16 defining thesecond exit gap 43 may be a sidewall of the housing 16 which alsodefines a portion of the electronics cavity 34. The first exit gap 45and the second exit gap 43 may permit the backlight cavity gas 25 toescape the backlight cavity 36 and rejoin the remainder of thecirculating gas 24.

A second entrance gap 41 may be located between the support 47 and therear plate 32. In exemplary embodiments, the second entrance gap 41 maybe located between a distal end of the support 47 and the front surfaceof the rear plate 32. A first entrance gap 39 may be located between thebrackets 48 and the housing 16. In exemplary embodiments the portion ofthe housing 16 defining the first entrance gap 39 may be a sidewall ofthe housing 16 which also defines a portion of the electronics cavity34. The second entrance gap 41 and the first entrance gap 39 may permita portion of the circulating gas 24 (i.e., the backlight cavity gas 25)to separate from the remainder of the circulating gas 24 and enter thebacklight cavity 36.

As previously described, in exemplary embodiments the first entrance gap39 is smaller than the second exit gap 43. In exemplary embodiments thesecond entrance gap 41 is smaller than the first exit gap 45. However,any size first entrance gap 39, second exit gap 43, second entrance gap41, and first exit gap 41 is contemplated.

FIG. 16 is another exemplary pressure analysis and data output similarto FIG. 6. The detailed data used to produce the graphicalrepresentation shown in FIG. 16 is as follows:

Medium-Fluid; Iteration=376

TABLE 5 X Y Z Pressure Temperature [in] [in] [in] [lbf/in{circumflexover ( )}2] (Fluid) [° C.] −13 −27 3.41 15.95534082 82.80915223 −13 03.41 15.95415027 78.80780428 −13 27 3.41 15.95314981 76.73172097 0 −273.41 15.95525719 89.47604249 0 0 3.41 15.95417125 89.92926056 0 27 3.4115.95312927 82.66170811 13 −27 3.41 15.95527029 92.04619987 13 0 3.4115.95415218 97.38758681 13 27 3.41 15.9531214 87.79855441 −13 −27 4.315.96863588 79.33436377 −13 0 4.3 15.96969667 76.02973785 −13 27 4.315.96581351 74.39993597 0 −27 4.3 15.96603453 80.51190665 0 0 4.315.95935343 80.63542739 0 27 4.3 15.96185612 75.60167989 13 −27 4.315.96510689 83.28837491 13 0 4.3 15.95824753 80.84146671 13 27 4.315.96025992 77.61727691

FIG. 17 through FIG. 19 illustrate an exemplary air flow velocityanalysis for the display assembly 10. As can be seen in these figures, aportion of the circulating gas 24 (i.e., the backlight cavity gas 25)may enter the backlight cavity 36 and travel therethrough at generally arelatively lower velocity as compared to the circulating gas 24traveling through the first gas pathway 22. Also, the angled sections 49may create an eddy of circulating gas 24 in an area 51 around the angledsections 49 resulting in slowed circulating gas 24 exiting the area 51.Regardless, this area 51 may comprise circulating gas at a relativelylow pressure as compared to the circulating gas 24 in the surroundingarea. The illustrated analysis is merely exemplary and is not intendedto be limiting.

Although the flow of the ambient air 44 and the circulating gas 24 maybe shown and described herein with respect to particular directions andorientations, it is contemplated that the ambient air 44 and thecirculating gas 24 may flow in other directions. For example, withoutlimitation, ambient air 44 and circulating gas 24 shown as flowingclockwise may flow counter-clockwise, when shown flowing vertically fromtop to bottom may flow from bottom to top, when shown flowinghorizontally from right to left may flow from left to right, when shownflowing vertically may flow horizontally, when shown flowinghorizontally may flow vertically, and the like.

Any embodiment of the present invention may include any of the optionalor preferred features of the other embodiments of the present invention.The exemplary embodiments herein disclosed are not intended to beexhaustive or to unnecessarily limit the scope of the invention. Theexemplary embodiments were chosen and described in order to explain theprinciples of the present invention so that others skilled in the artmay practice the invention. Having shown and described exemplaryembodiments of the present invention, those skilled in the art willrealize that many variations and modifications may be made to thedescribed invention. Many of those variations and modifications willprovide the same result and fall within the spirit of the claimedinvention. It is the intention, therefore, to limit the invention onlyas indicated by the scope of the claims.

What is claimed is:
 1. An apparatus for preventing bowing of an electronic display comprising: a housing; a cover panel, wherein the electronic display is located behind said cover panel; a backlight located behind said electronic display; and a closed loop pathway for circulating gas comprising: a first gas pathway located between said cover panel and the electronic display; a backlight cavity located between the electronic display and the backlight; and a second gas pathway located behind the backlight; wherein the closed loop pathway is configured to cause the pressure of circulating gas in the backlight cavity to be lower than the circulating gas in the first gas pathway.
 2. The apparatus of claim 1 further comprising: an open loop pathway for ambient air located behind said backlight.
 3. The apparatus of claim 2 further comprising: a rear plate located behind said backlight; a corrugated layer extending between said rear plate and said backlight; and a first open loop pathway located between said backlight and said rear plate.
 4. The apparatus of claim 3 further comprising: a heat exchanger located along the second gas pathway; and a second open loop pathway comprising said heat exchanger.
 5. The apparatus of claim 2 further comprising: at least one circulating gas fan located within the second gas pathway for moving the circulating gas through the closed loop pathway; and at least one ambient air fan located within the open loop pathway for moving the ambient air through the open loop pathway.
 6. The apparatus of claim 1 further comprising: a second cover panel; a second electronic display located behind said second cover panel; and a second backlight located behind said second electronic display; wherein the closed loop pathway for circulating gas further comprises: a third gas pathway located between said second cover panel and the second electronic display; and a second backlight cavity located between the second electronic display and the second backlight; wherein the second gas pathway is located between the backlight and the second backlight.
 7. The apparatus of claim 6 wherein: the second cover panel, the second display assembly, and the second backlight are oriented in a back to back arrangement with the cover panel, the display assembly, and the backlight, respectively.
 8. The apparatus of claim 1 further comprising: a first and second support located at an entrance and an exit, respectively, of the backlight cavity, wherein said first and second supports define an entrance gap and an exit gap, respectively, for the circulating gas to enter or exit the backlight cavity.
 9. The apparatus of claim 8 wherein: the entrance gap is smaller than the exit gap.
 10. The apparatus of claim 1 further comprising: a first and second bracket located at an entrance and an exit, respectively, of the backlight cavity, wherein said first and second brackets define an entrance gap and an exit gap, respectively, for the circulating gas to enter or exit the backlight cavity.
 11. The apparatus of claim 10 wherein: the entrance gap is smaller than the exit gap.
 12. The apparatus of claim 10 wherein: the second bracket comprises an angled section located on a distal end of said bracket and extending towards the side of said housing.
 13. The apparatus of claim 12 wherein: the angled section is configured to create a venturi effect on circulating gas passing from the first gas pathway to the second gas pathway.
 14. The apparatus of claim of 1 wherein: the pressure of the circulating gas passing through the backlight cavity is between 0 and 0.5 psi lower than the circulating gas passing through the first gas pathway.
 15. An apparatus for preventing bowing of an electronic display comprising: a housing; a cover panel, wherein the electronic display is located behind, spaced apart from, and substantially parallel to said cover panel; a backlight located behind, spaced apart from, and substantially parallel to said electronic display, wherein the space between the backlight and the electronic display defines a backlight cavity; a closed loop pathway for circulating gas encircling the electronic display and comprising the space between said cover panel and said electronic display, the backlight cavity, and a space between said housing and said backlight; an open loop pathway located in the space between said housing and said backlight; a first and second bracket located at an entrance and an exit, respectively, of the backlight cavity, wherein said first and second brackets define an entrance gap and an exit gap, respectively, for the circulating gas to enter or exit the backlight cavity, wherein the entrance gap is smaller than the exit gap; an angled section located on a distal end of the second bracket and extending towards the side of said housing; and a first and second support located at the entrance and the exit, respectively, of the backlight cavity, wherein said first and second supports define a second entrance gap and a second exit gap, respectively, for the circulating gas to enter or exit the backlight cavity, wherein the second entrance gap is smaller than the second exit gap.
 16. The apparatus of claim 15 wherein: the first and second brackets comprise a first set of apertures which define the entrance gap and the exit gap; and the first and second supports comprise a second set of apertures which define the second entrance gap and the second exit gap.
 17. The apparatus of claim 15 wherein: the electronic display comprises liquid crystals; and the backlight comprises light emitting diodes.
 18. An apparatus for preventing bowing of an electronic display comprising: a housing; a cover panel, wherein the electronic display is located behind said cover panel; a backlight located behind said electronic display and comprising a number of light emitting diodes; a closed loop pathway for circulating gas comprising: a first gas pathway located between said cover panel and the electronic display; a backlight cavity located between the electronic display and the backlight having an entrance and an exit; and a second gas pathway located behind the backlight and comprising a heat exchanger; a rear plate located behind said backlight; an open loop pathway comprising: first open loop pathway located in the space between said rear plate and said backlight; and a second open loop pathway comprising said heat exchanger; a first and second bracket located at the entrance and the exit, respectively, of the backlight cavity, wherein said first and second brackets comprise a first number of apertures defining an entrance gap and an exit gap, respectively, for the circulating gas to enter or exit the backlight cavity, wherein the entrance gap is smaller than the exit gap; an angled section located on a distal end of said second bracket and extending towards the side of said housing; and a first and second support located at the entrance and the exit, respectively, of the backlight cavity, wherein said first and second supports comprise a second number of apertures defining a second entrance gap and a second exit gap, respectively, for the circulating gas to enter or exit the backlight cavity, wherein the second entrance gap is smaller than the second exit gap. 